a lot of American companies don't like shipping/sending things outside of the USA, some of them are quite happy to tell you that its "just because" you aren't an American and they only sell to their own citizens due to personal beliefs and opinions, some others say that they don't want to be bothered due to paperwork or having to drive down to a fedex place or a UPS place, a few have told me that they have had scams and now dont trust any foreign buyers, and a couple have said that they have signed up to agreements with manufacturers not to sell outside the USA so that they have control over each countries pricing schemes just like with DVD regions etc...
I have bought things from the USA that were low value and had them sent USPS (united states postal service-like the royal mail) and had no problems, and I have had the same things sent via fedex and had them ripped open and pulled apart by UK customs who then promptly added duty, vat, handling and vat again, followed by a £14.00 parcel force handling fee, and being told to go 100 miles to the depot where the item was to pay up and sign/collect in person when they refused to deliver "due to being opened".....they were doing the delivery for fedex at the time as fedex don't do a lot of different locations end to end....
A lot of US sellers will only ship by fedex and refuse to budge even on a $5.00 screwdriver....this happens after they have your card details, resulting in me being sent a small screwdriver in a box big enough to send 2 pairs of work boots....was charged $108.88c shipping and got hit with £43.00 odd in taxes and charges due to the "value of the goods" assumed due to the fancy big box and printed shipping charge sticker.....phoned the seller, got an abrupt woman and tried to ask her not to do that again, got a mouthfull of abuse...
bottom line is if its a genuinely low value item worth only a few pounds and in a grey USPS mailer, it will usually get ignored in terms of unnecessary tax, if it gets sent in a huge box with a ribbon around it and a big "$$$$$$$$$ ship n handle" sticker it will get pummeled even if its only got a bag of sweets inside..
EX-Army : you need to contact the seller ASAP and get the battery removed and either buy a battery here or get it sent surface mail, it is now illegal to send rechargeable batteries and any batteries containing Lithium including non-rechargeable Lithium batteries by Air cargo/ Airmail due to a few mishaps that happened a while ago leading to fires and damage, I think this actually changed back in 2005......you need to get it removed or the US customs will take your cordless tools and you will lose them, they will not allow them onto a plane, even for mail inside the USA, which has to be sent surface as well and can take 2 weeks east to west...
the only batteries allowed onto airmail are regular consumer sized Alkaline( eg AA, AAA etc) in their original retail shop bought packets unopened, the seller will just try to send the rechargeable ones regardless as a lot of Americans don't even know that much about the rules/regulations, take a look at the US customs (US CBP) website and you will see this, as well as on our customs website....if your tools make it here by a great stroke of luck, which I doubt, then the UK jobsworths will destroy them at this side as a punishment for them making it onto the plane with the battery present...